<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <div id="app"></div>

  <script src="../js/17.0.1/react.development.js"></script>
  <script src="../js/17.0.1/react-dom.development.js"></script>
  <script src="../js/17.0.1/prop-types.js"></script>
  <script src="../js/17.0.1/babel.min.js"></script>
  <script type="text/babel">
    class Time extends React.Component{
      state = {
        date:new Date()
      }

      componentDidMount(){
        setInterval(()=>{
          this.setState({
            date:new Date()
          })
        },1000)
      }
      render() {
        return (
          <div>
            <h2>hello</h2>
            <input type="text"/>
            <span>现在是：{this.state.date.toTimeString()}
              <input type="text"/>
            </span>
          </div>
        )
      }
    }

    ReactDOM.render(<Time/>,document.getElementById("app"))
  </script>
</body>
</html>